The prior art is replete with various designs of static ventilators designed to be installed onto roofs in view of providing ventilation in attics. These static ventilators, conventionally made of galvanized steel, are usually provided with a base to be fixed to the roof under the roof covering, a vertical sleeve having an end connected to the base and a cover mounted to the free end of the vertical sleeve.
To install static ventilators onto sloping roofs, the connection between the vertical sleeve and the base has to be angled. One method used to connect the sleeve to the base is to cut an end of the sleeve at the known roof angle and then to solder the angled end to the base. A major drawback of this method is that the intense heat generated during the soldering operation weakens or destroys the rust-proofing treatment of the galvanized steel which eventually leads to water leaks.
Another method of joining the angled end of the sleeve to the base is to use plastic-cement type material to provide a leak proof joint. However, it has been found that, with time, the elasticity of such materials is greatly reduced by the constant exposure to the elements, again potentially leading to water leaks.
Canadian patent application No 2,009,776 filed on Feb. 9, 1990 by Claude E. MAHEU and entitled "TILTED SEAMLESS VENT AND METHOD FOR MAKING THE SAME" describes a method for making a seamless static vent where the vertical sleeve is integral with the base. While this is a major improvement over the conventional soldering method described hereinabove, a drawback of the method of Maheu is that a different static ventilator must be made for each roof angle.